I for one feel a little different on this matter. Although I am a little new to the big cat world I am sure in nature a big cat will snag a mammal from time to time. I do not see why their would be any problem at all with cats digesting animal fat. I also do not rememebring a decent thread or reasearch paper saying otherwise. I am sure an Aro in the wild will snag an occasional bird, bat, mouse, rat that falls into or is crossing the water. Look at a large mouth bass. That damn thing will eat snakes, rats, frogs, birds, fish, ect. IMO an occasional mouse will not hurt. Unless your talking about pinkys be ready to clean the filter of hair because it will not be digested. I think it could offer them a more wide variety of nutrition. I think cats out of anything would be more able to digest anything compared to many other fish. I would not make it a regualr thing becasue i am sure that would be a very low % of his diet in the wild. Now something like and armatus or similar fish that is obviously designed to handle fish only I wouldn't recommend. All just my opinion of course. Do be aware as stated above, the mouse/rat could scratch and bite. That all up to you.. I doubt the cat will care much, just thinks mmm mmm good!!!